SQL - UPDATE Statement

The SQL UPDATE statement is used to modify the existing records in a table. A SQL WHERE clause can be used with the UPDATE statement to update the selected rows, otherwise all the rows will be assigned the updated value.

Syntax

The syntax for using UPDATE statement is given below:

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition(s);

Example:

Consider a database containing a table called Employee with the following records:

• To update the City and Salary of an employee whose EmpID is 5, the SQL query is:

  UPDATE Employee
  SET City = 'Mumbai', Salary = 2900
  WHERE EmpID = 5;
  
  --see the update
  SELECT * from Employee;
  

  
  

  Now the Employee table will contain following records:

  EmpID	Name	City	Age	Salary
  1	John	London	25	3000
  2	Marry	New York	24	2750
  3	Jo	Paris	27	2800
  4	Kim	Amsterdam	30	3100
  5	Ramesh	Mumbai	28	2900
  6	Huang	Beijing	28	2800

• Similarly, to update the Salary of John who lives in London, the SQL query is:

  UPDATE Employee
  SET Salary = 3200
  WHERE Name = 'John' AND City = 'London';
  
  --see the update
  SELECT * from Employee;
  

  
  

  Now the Employee table will contain following records:

  EmpID	Name	City	Age	Salary
  1	John	London	25	3200
  2	Marry	New York	24	2750
  3	Jo	Paris	27	2800
  4	Kim	Amsterdam	30	3100
  5	Ramesh	Mumbai	28	3000
  6	Huang	Beijing	28	2800